645492 has 12 divisors (see below), whose sum is σ = 1506176. Its totient is φ = 215160.

The previous prime is 645481. The next prime is 645493. The reversal of 645492 is 294546.

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645492.

It is not an unprimeable number, because it can be changed into a prime (645493) by changing a digit.

645492 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26884 + ... + 26907.

2⁶⁴⁵⁴⁹² is an apocalyptic number.

It is an amenable number.

645492 is an abundant number, since it is smaller than the sum of its proper divisors (860684).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645492 is a wasteful number, since it uses less digits than its factorization.

645492 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53798 (or 53796 counting only the distinct ones).

The product of its digits is 8640, while the sum is 30.

The square root of 645492 is about 803.4251676416. The cubic root of 645492 is about 86.4231890775.

The spelling of 645492 in words is "six hundred forty-five thousand, four hundred ninety-two".